Do you suffer from gas or bloating after eating that is usually worse towards the end of the day? Do you have diarrhea or constipation? Do you notice an oily film in the toilet after you eat a high-fat meal? Are there many foods to which you have adverse reactions? If so, you may have small intestinal bacterial overgrowth (SIBO).

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SIBO is a condition that occurs when our normal gut bacteria which is usually found in greatest numbers in the colon (large intestine) is found in the small intestine. It is normal to have some bacteria in our small intestine, but when they are found in high numbers, we often experience the symptoms listed above.

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Under normal conditions in a healthy person, the migrating motor complex (MMC or 'intestine sweeper') causes intestinal contractions to occur about once every 90 minutes during the fasting state (between meals and during the night). These contractions move any remaining undigested food particles and bacteria out of the small intestine, preventing them from eating the food we ingest to fuel our bodies. When people graze all day, the MMC doesn't operate during the day, but will still occur while you sleep.

​Sometimes, after a person experiences a bout of food poisoning, they get the diarrhea, then notice in the months following that they have more gas and bloating than they did previously. Certain bacteria secrete a toxin that can damage the nerves in the gut. It is believed that this is one way that the movement of the MMC is hindered, and that when it doesn't clean the intestines as it is supposed to, SIBO can develop. Eating a lot of sugary foods and refined carbohydrates provides a lot of food for these bacteria, which also encourages an overpopulation of the small intestine.

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As I mentioned before, it is normal to have some bacteria in the small intestine. So what causes them to become too plentiful in the person who has never had food poisoning? One problem is our society today is that we feed these bacteria too well. If we have low levels of stomach acid (from high levels of stress, from taking acid blocking drugs or from damaged parietal cells in the stomach, etc) not only do we allow more pathogenic bacteria to survive in the stomach and make their way to the intestines, but we also don't have a strong signal to tell the pancreas to release the enzymes that we need to digest our food. When digestion is hindered, food sits in the small intestine for longer periods of time, giving the bacteria there more time to eat and more energy to reproduce, so you end up with more bacteria in the small intestine. The bacteria ferment the carbohydrates, causing gas. Gas can cause abdominal pain and cramping. It can be irritating to the small intestine to have partially-digested food and lots of bacteria there, and this can cause inflammation. Inflammation is characterized by heat, redness, swelling, pain or loss of function. We all have seen it when we've gotten an insect bite or a bad bruise. So what does inflammation do when it occurs inside the intestines?

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Inflammation in the gut can cause abdominal pain. It can also cause a condition called leaky gut that is often responsible for multiple food sensitivities. When there is swelling in the intestines, the 'tight junctions' between the cells become loose, allowing larger proteins to pass through into the blood vessels surrounding the intestines. The immune system recognizes these food proteins as foreign because they don't belong in the blood, so it makes antibodies to fight these 'invaders'. This, in turn, causes more inflammation. The more food sensitivities one has, the more difficult it is to avoid them all, and we have a vicious cycle. But......the good news....we know how to test for SIBO and how to treat it. We naturopathic doctors also have several effective strategies for supporting digestive function by helping the body make adequate amounts of stomach acid. I will leave this for another blog post.

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The lactulose breath test is an easy, non-invasive test for small intestinal bacterial overgrowth (SIBO). The hardest part about the test is the 3-day prep diet to clear away the food for the small intestinal bacteria, so that we can get an accurate test. In a nutshell, you cut out almost all carbohydrates for 1-3 days (I recommend a 3-day prep diet) prior to taking the test. This makes the bacteria very hungry and causes you to crave carbs and to be irritable.

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On the day of the test, you will blow once into a balloon-like device, then will drink a solution of lactulose. Our bodies don't absorb lactulose, so it stays in the small intestine so the bacteria can eat it. Certain bacteria produce certain gasses, like hydrogen, methane and hydrogen sulfide. You will blow into the balloon-like device every 20 minutes for 3 hours, then send all the tubes to the lab to have the gas in the tubes analyzed. By identifying the type of gas and the amount of each gas in each tube, we can determine which type of bacteria are present and can estimate how long it may take to eradicate them. I use anti-microbial herbs for treating the condition. After treatment, I often recommend a prokinetic, a substance that stimulates the movement of the MMC, be taken for about 3 months to prevent recurrence of SIBO. I also recommend a low FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) diet to keep inflammation down and heal up the gut. For more information on SIBO, refer to the website of my brilliant mentor, Dr. Allison Siebecker at www.siboinfo.com.

Inflammation in the gut can be caused by eating gluten when you have gluten sensitivity or celiac disease, eating foods to which you are allergic, ingesting dairy when you are lactose intolerant, as well as from a parasitic, bacterial or viral infection in the gut. I will save these topics for another post.